The present invention is directed to an apparatus for processing of semiconductor wafers, and in particular, to a processing tool with a lift and rotate assembly for use in processing the wafers.
Microelectronic devices are generally fabricated on and/or in microelectronic workpieces using different types of machines that typically perform several processing steps in one or more processing stations. To more fully automate the process and minimize operator handling, tools often have multiple processing stations and robotic handling equipment for moving semiconductor wafers or other types of workpieces from one processing station to the next.
One consideration for the tool architecture is the overall size of a tool. This is because integrated circuits are typically fabricated in clean rooms that are expensive to construct and maintain, which is related to the size of the space. As a result, efforts and developments that reduce the overall tool size can have a significant cost benefit.
Tool size can often be an important consideration when adding to and/or updating a particular tool in a line. If the size and shape of the new tool is equal to or smaller than the available space, or the space created by the removal of the old tool being replaced, the impact on nearby tools is minimized. In contrast, when a new or replacement tool is larger than the available space, or the space required by the previous tool, it can potentially require the adjustment and/or relocation of the placement of nearby tools.
One reason to update one or more tools in a semiconductor manufacturing line is to make a transition from a smaller to a larger wafer size. The use of larger wafer sizes is desirable because it enables a greater number of devices to be manufactured on each wafer. By producing more devices on each wafer the cost of manufacturing each device can often be reduced. For example, although the standard wafer size for many semiconductor manufacturing lines is 200 millimeters, there is an increasing trend toward using 300 millimeter wafers. Therefore, efforts at minimizing or maintaining tool size while also enabling the tool to handle larger wafer sizes would similarly be beneficial.
Another consideration for the tool architecture is ease of maintenance. Occasionally individual processing stations or individual components need to be removed for replacement or regular cleaning maintenance. The easier it is to service the assembly or subassembly requiring maintenance, the less time a tool will be down or out of service.
The downtime for such tools is an important performance parameter in light of the large capital cost for the tools and the costs of clean room environments. In clean room environments, personnel typically wear protective clothing including gloves, coats, masks, etc., which can make even routine tasks more cumbersome. Therefore improvements in accessibility of installed assemblies and/or subassemblies and the ease of installation and/or removal of the same would similarly be beneficial.
The present invention is directed toward a lift and rotate assembly for use in a workpiece processing tool. Several embodiments of the lift and rotate assembly are mounted to the tool so that they enhance the use of space inside a cabinet of a tool. This provides more room for larger processing stations and/or reduces the xe2x80x9cfoot printxe2x80x9d of the tool (i.e., the floor space occupied by the tool). For example, larger processing stations for larger wafers (e.g., 300 mm) can be used in at least approximately the same space as was previously possible for smaller wafers (e.g., 200 mm). Several embodiments of the lift and rotate assembly also provide easy access to the mechanical and electrical components of the lift/rotate assemblies without having to remove the lift and rotate assembly from the tool. This feature reduces the time for servicing and repairing of the lift/rotate assemblies. Additionally, the mechanical and electrical components of the lift/rotate assemblies can be accessed without having to open a lower compartment of the cabinet where the chemical storage tanks and fluid lines are housed. This is beneficial because operators and other personnel are not exposed to chemical vapors when the lift/rotate assemblies are serviced. Several embodiments of lift/rotate assemblies also provide easy access to reaction chambers and other components in the cabinet because they can tilt outward without having to be removed from the cabinet to reduce the time and effort required to service components of the tools inside of the cabinet.
In one embodiment, the lift and rotate assembly comprises a body and a process head for receiving a workpiece. The body contains a lift mechanism for lifting a portion of the body and the process head as a unit with respect to another portion of the body that mounts to the processing tool. The process head is rotatably coupled to the body to enable the process head to rotate with respect to the body and the processing tool. Under one aspect of the invention, the lift and rotate assembly is a modular unit removably attached to an exterior portion of the workpiece processing tool in a position that can be easily accessed and serviced from outside of the workpiece processing tool. The modular unit provides an increased flexibility for changing the configuration of the workpiece processing tool and for the interchangeability of the processing components of the tool while minimizing the down time of the processing tool. The modular unit also allows, as one example, the workpiece processing tool to have a smaller footprint in a clean room. Alternatively, the workpiece processing tool can be configured to handle larger workpieces without having to increase the tool""s footprint within the clean room.
In one embodiment of the invention, the body of the lift and rotate assembly has first and second portions, the first portion being releasably connected to an exposed surface of the frame of the workpiece processing tool. The body""s second portion is connected to the first portion and the process head. The body""s second portion and process head are movable relative to the first portion between raised and lowered positions. Control components are connected to the body and configured to move the body""s second portion between the raised and lowered positions. The body, the control components, and the process head from a modular unit are removable as a unit from the exposed surface of the frame. This modular unit can be easily removed from the frame and replaced with another unit to minimize downtime of the workpiece processing tool.
In one embodiment, the lift and rotate assembly is easily accessible from outside of the processing tool while mounted on the tool""s frame. Accordingly, the lift and rotate assembly can undergo service, repair, or maintenance from outside of the processing tool without having to access the interior compartment of the workpiece processing tool.
Under one aspect of the invention, the lift and rotate assembly is pivotable relative to the frame between a forward, operating position and a tilted, service position. In the forward, operating position, the body""s first portion is adjacent to the frame, and in the tilted, service position, the body""s first portion is tilted away from the frame. When the lift and rotate assembly is in the tilted, service position in one embodiment, the lift and rotate assembly is positioned to allow easy access into the interior area of the workpiece processing tool for service, repair, or maintenance, of other components of the processing tool.
Under another aspect of the invention, the body""s first portion includes a housing that contains the control components. An access panel is connected to the housing and is movable relative to the housing between open and closed positions when the body is connected to the frame. A plurality of the control components are mounted on the access panel and are accessible from the exterior of the workpiece processing tool while the lift and rotate assembly is connected to the frame. Accordingly, the control components can be easily and quickly accessed for repair, replacement, or maintenance.
Under another aspect of the invention, a processing tool is provided for processing selected workpieces. The processing tool provides a frame, a deck attached to the frame and a processing chamber coupled to the deck inboard of the frame. A lift and rotate assembly is removably mounted to an exposed surface of the frame and spaced outboard of the deck. The lift and rotate assembly has a body, control components, and a process head. The body is releasably connected to the exposed surface of the frame. The control components are connected to the body and positioned to cause a portion of the body and the process head to move relative to the deck between the raised and lowered positions. The body, the control components, and the processing head are removable from the frame as a unit.
In yet another aspect of the invention, a method is provided for servicing a lift and rotate assembly of a workpiece processing tool. The lift and rotate assembly has a body and a process head connected to the body. The method includes accessing the body from the exterior of the frame when the lift and rotate assembly is mounted on the frame. The body includes a housing that contains control components, and an access panel is mounted on the housing. The method further includes moving the access panel to an open position to expose the control components while the lift and rotate assembly is mounted on the frame, and servicing the control components in the housing from exterior of the workpiece processing tool while the lift and rotate assembly is connected to the frame.
Another method includes moving a second portion and the process head relative to a first portion of the body to the raised position, engaging the body from a position exterior of the frame, and tilting the body and the process head as a unit relative to the frame to a tilted, service position. The method of one embodiment also includes servicing the lift and rotate assembly while connected to the frame and in the tilted, service position.